Abstrict

An apparatus for automatically removing cake deposits from the
surface of filter cloths within a filter press is disclosed. The
apparatus includes a rod for suspending the cloth in a substantially
inverted "V"-shaped configuration. The cloth is then slackened
by lowering a rod over which the cloth is folded. The rod is then
suddenly forced upwardly under the driving force of a loading means.
The rod draws the cloth to a taut, tensioned condition, imparting
a whip-like motion to the fabric of the filter cloth. This imparted
motion serves to disengage the cake from the filter cloth.

Claims

I claim:

1. An apparatus for removing filter cake in a filter press having
a plurality of filter plates mounted within a frame; said filter
plates being adapted for opening, including first and second adjacent
filter plates, a pair of scissor-like suspension arms pivotedly
mounted to each pair of adjacent filter plates an elongate horizontal
first rod mounted above and between each pair of said adjacent filter
plates, and a filter cloth, folded over the horizontal rod, and
secured to the first and second filter plates, said apparatus comprising:

a second elongate rod mounted above said filter press and parallel
said first rod, said second rod being connected to said first horizontal
rod by means of a cable; said first rod being positioned to suspend
said filter cloth in a tensioned, substantially inverted "V"-shaped
configuratrion between any opened said first and second filter plates;
and

a return means mounted on each filter plate for rapidly returning
said second rod to an equilibrium position subsequent to a displacement
of said second rod; said return means comprising:

a first compression plate mounted on said suspension arms;

a first spring mounted on top of said first compression plate;

an elongate first shaft mounted on said second horizontal rod,
having a first longitudinal axis; said first shaft extending through
said first compression plate and through said first spring;

a second compression plate mounted on said elongate shaft wherein
said first spring is positioned between said first and second compression
plate; wherein a displacement of said second rod in a first direction
effects a compression of said first spring along said first longitudinal
axis;

a carriage mounted to slide along said frame;

an impact-loading means mounted on said frame said impact loading
means comprising:

a first pneumatically operated cylinder having a second shaft,
reciprocally slidable piston mounted therein; wherein said piston
is driven in a first direction upon pressurized air being supplied
to said cylinder;

a second spring mounted on said cylinder and over said second shaft
wherein said second shaft extends through said second spring;

a third compression plate mounted on said second shaft wherein
said second spring is mounted between said third compression plate
and said cylinder wherein a displacement of said second shaft in
said first direction effects a compression of said second spring;
along said second longitudinal axis;

wherein a pneumatic pressure is applied to said piston inducing
a displacement of said piston effecting a first direction displacement
of said third compression plate with a corresponding displacement
of said second rod; said second spring being compressed by said
third compression plate's first direction displacement; said first
rod being displaced in said first direction under the force of gravity
as said second rod is displaced in said first direction; said first
rod's first direction displacement operating to ease any tension
applied to said filter cloth by said first horizontal rod;

wherein, thereafter; upon said pneumatic pressure on said piston
being released, said second spring effects a rapid displacement
of said third compression plate in said second direction thereby
applying a sudden impact, tensioning load to said filter cloth through
a displacement of said second horizontal rod in a second direction
to effect a snapping motion in said filter cloth and thereby remove
said filter cake from said filter cloth.

2. The apparatus of claim 1 wherein said cable is generally annular
in shape thereby defining a central opening and wherein said first
rod and said second rod pass through said central opening.

3. The apparatus of claim 2 wherein a shifting mechanism adapted
to separate each said pair of adjacent filter plates is mounted
on said carriage.

4. The apparatus of claim 3 wherein said third compression plate
of said impact-loading means is dimensioned to extend along a plurality
of opened, adjacent filter plates and contact each respective second
rod of each pair of adjacent filter plates wherein a pneumatically
induced first direction displacement of said second rods by said
third compression plate facilitates a gravity induced displacement
of each of said corresponding first rods of said plurality of filter
plates and a subsequent release of pneumatic pressure on said third
compression plate effects a rapid second direction displacement
of each of said first rods thereby effcting a snapping motion in
each respective filter cloth of each pair of said plurality of filter
plates thereby removing said filter cloth from said filter cloths
simultaneously.

5. In a filter press having a plurality of filter paltes defining
opposite sides and opposite abutting faces, including a first and
a second adjacent filter plates, having a filter medium disposed
along the filtering surfaces of said first and second adjacent filter
plates, a device for removing filter cake from said filter medium,
said device comprising:

a horizontal rod mounted above and between said pair of filter
plates, said filter medium being folded over said rod whereby said
filter medium is held in a substantially inverted "V"-shaped
configuration;

at least one pair of suspension arms, each arm having a first end
pivotedly mounted on a side of said first filter plate and a second
end pivotedly mounted on a corresponding side of said second filter
plate;

a plurality of springs, at least one spring being mounted on each
suspension arm;

a connection shaft mounted on each of said springs whereby a first
displacement of said connection shaft results in a compression of
said spring and a second displacement of said conenction shaft results
in a release of said compressed spring, said connection shaft being
connected to said horizontal rod whereby said first displacement
operates to displace said hroizontal rod in a first direction, slackening
said filter medium, thereby reducing any tension thereon, said second
displacement in a opposite second direction operates to tension
said filter medium by impact-loading said filter medium; and

a third compression plate made mechanically cooperable with said
connection shaft;

an actuation means for displacing said third compression plate,

said actuation means comprising:

a pneumatic piston-fitted cylinder, having a drive shaft extending
thereform adapted to be reciprocably displaced by said piston, said
drive shaft being displaceable in a third direction by introduction
of pressurized air into said cylinder, said drive shaft being mounted
to said third compression plate;

a return spring mounted on said drive shaft, between said cylinder
and said third compression plate wherein a displacement of said
drive shaft in said third direction effects a compression of said
return spring and wherein a release of said pressurized air effects
a rapid displacement of said third compression plate in a fourth
direction, said fourth direction being opposite from said third
direction;

wherein a pneumatically induced displacement of said compression
plate effects a first direction displacement of said rod and a slackening
of said filter cloth and wherein a rapid fourth direction displacement
of said third compression plate by said return spring effects a
rapid second direction displacement of said rod, induced by said
spring;

wherein said actuation means facilitates a repeated first and second
displacement of said rod for each opened pair of adjacent filter
plates;

wherein said compression plate adapted to contact and displace
said connection means to effect a first displacement of said spring
and thereafter to retract, permitting a second displacement of said
spring, thereby effecting a snap-like motion of said filter medium
by impact-loading.

6. The filter press of claim 5 wherein said actuation means is
mounted on a carriage which is slidably mounted on said frame.

7. The filter press of claim 6 wherein a shifter means for separating
each pair of adjacent filter plates is mounted on said carriage.

8. An apparatus for automatically removing cake from a filter cloth
in a filter press having a plurality of parallel positioned filter
plates mounted within a frame, said filter plates having oppositely
positioned abutting faces and opposite sides, said apparatus comprising:

a plurality of first and second adjacent filter plates,

a first elongate horizontal rod positioned between each pair of
filter plates;

a second horizontal elongate rod positioned between each pair of
filter plates, and a pair of filter cloths a first filter cloth
having a first proximal end, fixedly mounted to a first filter plate,
and a first distal end mounted on the first elongate, horizontally
positioned rod, a second filter cloth having a second proximal end
fixedly mounted to a second filter plate and a second distal end
mounted on the second elongate, horizontally positioned rod, said
first and second rods being positioned between said abutting first
and second filter plate faces

a pair of filter cloth suspension arms, each pair of suspension
arms being pivotedly mounted to each adjacent pair of filter plates,
each pair of suspension arms having a proximal end pivotedly mounted
to said first filter plate and a distal end pivotedly mounted to
said second filter plate;

a first compression plate mounted on each said pair of suspension
arms,

at least one spring fixedly mounted on each said first compression
plate,

an elongate first shaft mounted slidably through each first compression
plate, each said first shaft extending through said spring, said
first shaft having a first longitudinal axis;

a second compression plate fixedly mounted on each said first shaft
wherein each said spring is positioned between a respective said
first compression plate and a respective said second compression
plate;

a third elongate rod fixedly mounted on said first shafts, said
third rod being positioned parallel to said first and second rods,
wherein a first direction displacement of said third rod, parallel
said first longitudinal axis, effects a compression of said spring
and an oppositely directed, second directioned displacement of said
third rod effects a release of said compression of said spring;

a cable having a first end and a second end, said first end being
mounted on said first rod, said second end being mounted on said
second rod, a center region of said cable being draped over said
third rod, wherein a displacement of said third rod in said second
direction effects a corresponding second direction displacement
of said first and second rods and wherein a first direction displacement
of said third rod facilitates a gravity induced first directioned
displacement of said first and second rods, said third rod being
movable between two conditions, a first condition wherein said spring
is compressed and said filter cloths are made substantially untensioned
and slack, and a second condition wherein said spring compression
is suddenly released, and said spring effects a snap-like, impact-loading
tensioning of said filter cloths; and

an actuation means made mechanically cooperate with said spring
and adapted to control the motion of said spring between said first
condition and said second condition.

Description

BACKGROUND OF THE INVENTION

1. Field

This invention relates to filter presses, specifically those designed
to separate solids from liquids. More particularly, this invention
is directed to presses which utilize a fabric filter cloth as a
means of removing solids from liquid systems.

2. Statement of the Art

Technical attention has long been devoted to the processing of
solids-bearing liquids, such as slurries and other suspended solids
systems. Of prominence among the conventional means adopted to process
these liquid-solid suspensions is the plate and frame filter press
which typically includes a series of parallel, generally vertically
oriented filter plates which are covered by a fabric filter cloth.
The plates, during operation of the filter, are held in an abutting
arrangement. In this arrangement, a plurality of enclosed spaces
are defined between each pair of adjacently positioned plates. The
liquid-solid suspension to be filtered is injected under pressure
into the enclosed spaces. The suspension is forcibly directed through
the filter cloths whereupon the solids within the suspension are
deposited on the surface of the filter cloths. Recognizably, after
a period of operation, the cloths become sufficiently laden with
solid deposits that further efficient operation of the press requires
the plates to be separated and the solid deposits to be removed
from the cloths.

In those instances wherein the solid deposits or filter cakes slightly
or moderately adhere to the filter cloth, the mere opening of the
abutting plates will often result in the cake falling off the filter
cloths under the force of gravity. In those cases wherein the cake
is in a sticky engagement with the filter cloth, other means are
required to successfully separate the cake from the filter cloth.

A conventional approach to the cake having a sticky engagement
with the filter cloth has been a physical removal of the cake from
the cloth with a scraper. Noticeably, this approach involves a serious
likelihood that the cloth may be damaged by the abrasive contact
between the scraper and the cloth. Further, provision of a scraper
typically requires the employment of a worker to manipulate that
scraper. Various methods have also been proposed directed to automating
the process of filter cake removal.

U.S. Pat. No. 3,622,005 to Kurita discloses a frame assembly adapted
with means of suspending a filter cloth between each pair of the
open filter plates. The cloth is suspended in a modified inverted
"V"-shaped configuration. The solids are deposited on
the interior surfaces of the filter cloth forming the "V"-shaped
configuration, thereby initially permitting a gravitationally induced
removal of the cake from the filter cloth surface. Thereafter, the
disclosure suggests an oscillating or vibrational action being transferred
to the cloth by means of a spring-biased actuation assembly.

U.S. Pat. No. 3,669,273 to Kurita adopts a similar vibration-based
approach by providing a filter cloth suspension system which employs
a cloth support which is vibrated by the motion of a spring associated
with a superiorly positioned trolley which travels along a wave-like
rail surface. This system utilizes a modified "V"-shaped
suspension approach by adopting a nonsymmetrical suspension support
of the cloth in order to initiate the travel of the trolley along
its rail.

In U.S. Pat. No. 4,397,744 to Haruo, a vibrational motion is transferred
to each inverted "V"-shaped filter cloth by means of a
support arm having a series of wave-like undulations in the surface
thereof. The support arm is pivotedly mounted on its one end to
a filter plate. As adjacent filter plates are opened, i.e. separated,
the support arm is pulled over a support which interacts with the
undulated support arm surface to effect an oscillating motion to
the support arm. The support arm is linked through a spring to a
rod supporting the filter cloth. As the support arm oscillates,
the filter cloth is made to vibrate.

In those instances wherein the filter cake is composed of a thioxotropic
material, the addition of energy to the cake by a vibrational system
may operate to complexify, if not hinder, the removal of the cake
from the cloth. Specifically, thioxotropic material by definition
tends to "puddle," i.e. become fluid upon the placement
of shear forces on the mass of the material. In subjecting the cakes
to vibrational action, shear forces are generated on the cake at
the interface of the cake and filter cloth, and further within the
mass of the cake itself. It follows that vibration tends to transform
portions of the cake into a fluid which often is more sticky in
its adhesion or engagement with the filter cloth than the unvibrated
cake.

In the event the vibrated cake develops fluidized pockets or strata
within the cake itself, it is likely that the cake would slough
off portions thereof as opposed to falling from the filter in toto.
The disclosures of Kurita define mechanisms which induce a damped
vibrational action within the suspended filter cloth, i.e. the vibration-inducing
action of the actuating apparatus is translated to the filter cloth
through means of a spring which in turn dampens the motion of that
actuating apparatus. The dampening of that motion tends to encourage
a series of vibrations which are of low intensity, thereby facilitating
considerable energy transfer to the filter cake.

SUMMARY OF THE INVENTION

An apparatus for removing filter cake in a filter press is disclosed.
An apparatus constructed in accordance with the instant invention
is adapted for association with a filter press which includes a
plurality of filter plates mounted in essentially parallel and upright
fashion upon a frame assembly. The filter plates are mounted with
means for moving the plates along the frame assembly to facilitate
the opening, i.e. the separation, of each abutting pair of plates.

The filter press of the instant invention typically includes a
filter cloth or medium which is positioned upon an abutting face
of each filter plate, i.e. between each pair of filter plates in
a conventional manner. The filter cloth is suspended from a horizontal
rod typically mounted above and between each pair of plates. The
filter cloth or medium is typically folded over the horizontal rod.
Further, the filter cloth is conventionally secured at each of its
ends to a respective lower portion of the respective abutting filter
plates. This arrangement of horizontal rods, together with a filter
cloth securely positioned at its end sections to abutting adjacent
filter plates, results in an essentially inverted "V"-shaped
cross-sectional configuration or orientation of the filter cloth
upon the opening or separation of each adjacent pair of filter plates.

The instant invention is directed towards a means and method of
impulse- or impact-loading the filter cloth through means of the
horizontal rod support, whereby the filter cloth is suddenly drawn
taut under tension from a substantially untensioned, slackened position
whereby the cake or other debris which are deposited on the surface
of the filter cake are forcefully ejected by the whip-like or snapping
motion imparted to the fabric of the filter cloth.

An apparatus constructed according to the instant invention generally
includes a filter cloth suspension means mounted above the filter
press and adapted to suspend the filter cloth in a tensioned orientation,
e.g. a substantially inverted "V"-shaped configuration,
upon the opening of the adjacent filter plates housing the filter
cloth. The suspension means may also function as a mounting platform
for an impulse- or impact-loading means which is adapted to ease
and substantially lessen any tension applied to the filter cloth
by the horizontal rod by displacing that rod downwardly. The displacement
of the rod downwardly causes the filter cloth to reach a slackened
condition. Thereafter, the impact-loading means suddenly applies
an impact-tensioning load to that filter cloth through a rapid displacement
of the horizontal rod upwardly, thereby bringing the filter cloth
to a taut condition. This sudden tensioning of the filter cloth
imparts a whip-like or snapping motion to the cloth which results
in the displacement of the filter cake from the surface of the filter
cloth. The instant invention is not directed toward vibrating the
filter cloth. Instead, the displacement of the cake from the filter
cloth results from a sudden and violent snapping of the slackened
filter cloth as opposed to an oscillating or vibrationally induced
motion within the cloth.

In a preferred embodiment, the filter cloth suspension means includes
generally a pair of suspension arms which are positioned on each
of the opposed sides of each respective pair of filter plates. The
suspension arms are mounted pivotedly at their proximal end to a
first adjacent filter plate and at their distal end to a corresponding
positioning on the opposing second adjacent filter plate.

Each suspension arm may include a pivoted juncture positioned proximate
the midpoint of the suspension arm whereby the suspension arm adopts
an essentially "U"-shaped or "V"-shaped configuration.
The pivoted juncture permits the suspension arm to open and close
as the corresponding adjacent filter plates are opened and closed.
The invention is also adapted for the opening of a plurality of
adjacent filter plates and their subjection to a simultaneous filter
cake-removing force application.

Positioned on the suspension arms is an impulse- or impact-loading
means which may be a resilient elastic member. In a preferred embodiment,
this loading means may be a plurality of spring members, e.g. coil
springs, which are positionable between two orientations or conditions--a
first condition wherein energy, which is typically resultant from
the spring being compressed under the action of a driven contact
plate into a compressed orientation, is stored in the loading means
(e.g. springs); and a second condition wherein the driven compressive
action of the contact plate is released suddenly, permitting the
spring member to return to an equilibrium position and thereby effecting
a rapid, upward displacement of the horizontal rod and an accompanying
whip-like or snapping motion being induced within the filter cloth.

A proximal end of each spring member is fixedly mounted to the
suspension means. The distal end of each spring member is mounted
in contact with a first contact plate, which plate is displaceable
between the described first condition wherein the spring is compressed
and a second condition wherein the plate does not effect a compressing
action upon the spring and in fact may actually not be in contact
with the distal end of the spring.

The first contact plate may include a first connection means which
extends from the plate and further may extend through the interior
of a coiled spring. The first connection means may include a horizontally
positioned bar which extends essentially parallel to the horizontal
rod. The horizontal bar member includes a second connection means
adapted to connect with the horizontal rod. The first connection
means is fitted with an abutment surface. The first abutment surface
is adapted to be contacted and driven by a second contact means
which itself is adapted to be moved between two distinct conditions--a
first condition in which the contact plate effects a driven downward
displacement of the first connection means and thereby effects a
downward displacement of the horizontal rod; and a second condition
wherein the second contact plate is essentially retracted suddenly
from the abutment surface of the first connection means, and in
effect may actually be withdrawn from contact with the abutment
surface of the first connection means. This retraction permits the
spring which is compressed under the first condition to expand and
direct the horizontal rod suddenly upward, thereby drawing the cloth
taut by a tensioning impulse- or impact-loading of the filter cloth.
This sudden displacement of the cloth effects a whip-like or snapping
motion within that filter cloth which discharges the cake deposits
from the filter cloth.

The second contact plate is actuated by a driving actuation means.
This actuation means may include pneumatic or hydraulic means adapted
to effect the downward displacement or first condition of the second
contact plate. A secondary spring means which may be fitted to the
second contact plate is adapted to effect a sudden and rapid retraction
of the second contact means from the abutment surface upon the release
of the downwardly driving force on the second contact means.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a conventional filter press fitted with
the filter cake removal apparatus of the instant invention. As shown,
the new apparatus is fitted on the top or upper portions of the
filter press;

FIG. 2 is a perspective elevational view of the actuation means
of the filter cake removal apparatus of the instant invention. FIG.
2 includes a cut-away view;

FIG. 3 is a side view of the suspension means and attendant impact-loading
means of the instant invention showing the filter cloth in an essentially
taut, tensioned and impact-loaded condition prior to the discharge
of the cake from the filter cloth surface;

FIG. 4 is a side view of the instant invention similar to that
shown in FIG. 3 wherein the filter cloth is shown in a substantially
untensioned or slackened orientation;

FIG. 5 is an elevational perspective view of a portion of a suspension
means of the instant invention adapted for supporting the filter
cloth;

FIG. 6 is an elevational perspective view of a portion of an alternative
suspension means of the instant invention adapted for supporting
the filter cloth; and

FIG. 7 is a partial side view of a filter press of the instant
invention adapted for simultaneous multiple plate opening and cake
removal.

DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

As shown in FIG. 1, a conventional filter press includes generally
a frame assembly 15 which provides an essentially channel-like construction
for the containment of a series or plurality of filter plates 17.
Filter plates 17 are generally of a rectangular, planar configuration
and are oriented in a substantially upright positioning. As shown,
the filter plates 17 are positioned parallel one another such that
each plate, generally 10, is in an abutting relationship with an
adjacent plate, generally 19. The plates 17 are driven along the
channel defined by frame assembly 15 under the action of a power-driven
head, generally 21. The frame assembly 15 is fitted with means shown
generally as separation means 16. Separation means 16 is of a type
conventionally known in the art, such as that shown in U.S. Pat.
No. 4,105,560 (Fismer). Separation means 16 is adapted for separating
or opening each pair of plates 17. The invention also contemplates
a separation means such as shown in Fismer wherein a multiplicity
of pairs of plates 17 may be simultaneously opposed as shown in
FIG. 7. As shown, two plates 23, 24 are in an opened position, that
is, each plate is substantially removed from an abutting relationship
with one of its adjacent plates, thereby exposing a filter cloth
27 which is positioned between the abutting faces 29, 31 of the
respective plates 23, 24.

Filter cloth 27 is generally rectangular in configuration and,
as shown, includes a proximal end 33 which is substantially fixed,
or alternately securely fastened, to the lower regions 35 of the
plate 23. Similarly, the distal end 37 of the filter cloth or medium
27 is fixedly mounted to the lowermost regions 39 of plate 24.

As shown in FIG. 6, the filter cloth 27 is folded or draped proximate
its central portion over a horizontal rod 41 which extends essentially
parallel to the planes of abutting faces 29, 31 of the respective
plates 23, 24. Horizontal rod 41 is positioned substantially above
and between the plates 23, 24. The horizontal rod 41 in suspending
the filter cloth imparts a substantially inverted "V"-shaped
configuration or orientation to the filter cloth 27. Alternately,
as shown in FIG. 5, the filter cloth 27 may include two separate
panels 28, 30 which are each draped and secured to a respective
horizontal rod 41A and 41B. Horizontal rods 41A, 41B similarly function
to suspend the filter cloth in an essentially inverted "V"-shaped
cross-sectional configuration.

As shown in FIGS. 1 and 4, the filter cloth 27 is positionable
within a variety of configurations. These configurations result
essentially from variations in the elevation or orientation of the
horizontal rod 41. A displacement or positioning of the horizontal
rod 41 at a lower elevation results in the filter cloth 27 being
substantially slack and untensioned. As shown specifically in FIG.
1, this slackened condition generally results in the surface of
filter cloth 27 adopting an irregular as opposed to a smooth linear
cross-section. The irregularity is in part resultant from the deposits
of solids or cake materials 42 which are positioned on the interior
facing surfaces 43, 45 of the filter cloth 27. As the cloth 27 is
slackened, cracks or fissures may result in the cake deposits, thereby
encouraging a displacement of some of the cake from the surface
of filter cloth 27.

The horizontal rod 41 is held in position by the action of connection
means 47. As shown in FIG. 2, connection means 47 may comprise a
substantially cable-like member 48 which is positioned around the
circumference of the horizontal rod member 41 and extends upwardly
to be secured about a bar member 49 within a channel 50 defined
within that bar member 49. Bar member 49 extends essentially parallel
to horizontal rod 41 substantially along its complete length. Alternately,
as shown in FIG. 4, the rod 41 may be connected to a connection
means 51 which includes an essentially shaft-like member 52 which
extends downwardly and is fixedly mounted on the horizontal rod
41.

In both constructions, either the horizontal bar 49 or the connection
means 51 is fitted to an upwardly extending shaft 53. Shaft 53 extends
upwardly and is fitted proximate its end 55 to a first contact plate
57. As shown, contact plate 57 may be an essentially planar member
having a sufficient contact surface to abut against a spring-like
or elastic member 58. Spring-like member 58 may be a coil spring.

Contact plate 57 is securely held from displacement toward the
end 55 of shaft 53 by a restraining means 59. This restraining means
59 may be an interiorly threaded nut 61 which is fitted about a
threaded portion 62 of the shaft 53. Spring 58 is fitted at its
distal end 63 to a platform 73. Platform 73 is mounted on a rod
75 which forms the pivot 77 of suspension arms 65. Rod 75 extends
between the pairs of suspension arms 65 which are located at opposing
sides of the frame assembly 15 (not shown). As shown, suspension
arms 65 may each include a pair of auxiliary arm members 67 which
are pivotedly mounted at point 69 so as to be rotatable about pivot
point 69. The distal end 71 of each arm 67 is pivotedly mounted
on the opposing upper structural region of each pair of adjacent
filter plates 23, 24, thereby defining an essentially inverted "V"-shaped
configuration which is expandable about pivot point 69; i.e., upon
filter plates, generally 81 and 83, being displaced in the directions
indicated generally by 85, the ends 71 of auxiliary arms 67 are
likewise displaced along directions 85. Upon the filter plates 23,
24 being brought into abutment, the ends 71 of arms 67 are likewise
brought into close proximity.

Positioned proximate the horizontal bar 49 is a second contact
plate 90. In FIG. 2, this contact plate 90 is shown as a substantially
rectangular planar member. Contact plate 90 abuts against bar 49
on an abutment surface, generally 92. Contact plate 90 is mounted
on a threaded shaft 94 which extends from a pneumatic or hydraulic
piston, generally 96. As shown, piston 96 is mounted on a movable
carriage 99 which also carries separation means 16. The threaded
shaft 94 is dimensioned to be slidably received within an aperture
98 within the contact plate 90. A portion of shaft 94 extends through
an aperture 98 in contact plate 90 and is fitted with a retaining
means 99, e.g. a threaded bolt 100, which retains the contact plate
90 against any upward displacement.

An auxiliary spring 102 is mounted in abutment against the side
104 of plate 90 opposite the retaining means 99. The distal end
106 of spring 102 is mounted in abutment against piston 96 such
that upon the driven displacement of contact plate 90 downwardly,
i.e. in the direction indicated by arrow 108, the spring 102 is
compressed, thereby storing energy. Upon the piston 96 removing
any downwardly directed force application to the contact plate 90,
e.g. in the case of a pneumatic piston by releasing air pressure
through outlet 110, the spring 102 forcefully directs the contact
plate 90 upwardly, thereby releasing any downwardly directed force
application upon bar 49.

As shown in FIG. 7, the construction of the instant invention may
facilitate a multiple filter plate processing wherein a plurality
of adjacent filter plate pairs, as opposed to a single pair of such
plates, are opened by the separation means 16. Thereafter, the second
contact plate 90 which extends sufficiently so as to contact the
abutment surface 92 of each respective pair of plates 17 is driven
downwardly by the simultaneous action of two pistons 96 which are
individually positioned on opposing ends of the second contact plate
90.

In operation, a filter press having a plurality of upright, abutting
filter plates 23, 24 is injected with solids-bearing liquid. The
liquid, in passing through filter cloths 27 arranged between each
pair of abutting plates 23, 24 deposits the solids suspended therein
on the filter cloths 27. Upon draining the liquid, each pair of
adjoining plates 23, 24 is systematically separated, i.e. opened.
Upon the opening of each pair of plates 23, 24, the respective filter
cloth 27 is oriented in a substantially inverted "V"-shaped
cross-sectional configuration due to the support action of horizontal
rod 41 positioned above and between the adjacent plates 23, 24.

The rod 41 is then forced downwardly by the action of a driven
second contact plate 90 which is driven by a pneumatic, hydraulic
or other power source 96. Upon being forced downwardly, the rod
41 permits the filter cloth 27 to reach a slackened, substantially
untensioned orientation. The downward displacement of rod 41 is
resisted by a plurality of springs 58 which are connected to the
horizontal rod 41 by a linkage assembly or first connection means.
Upon the rod 41 reaching a predetermined elevation or position,
the driving force on the second contact plate 90 is suddenly released.
An auxiliary spring 102 mounted on the second contact plate 90 operates
to forcefully retract plate 90 from its association with rod 41.

At this juncture, the plurality of springs 58 operate suddenly
and rapidly to displace the rod 41 upwardly, resulting in the rod
41 impacting against the filter cloth 27 and bringing that cloth
to a taut and tensioned orientation. The force of the rod 41 against
the cloth 27 results in a whip-like motion within the fabric of
the cloth 27 which serves to knock the cake deposits 42 from the
surface of the cloth. Further, the force of gravity operates to
cause the cake 42 to fall downwardly away from the surface of filter
cloth 27.

It is to be understood that the embodiments herein described are
merely illustrative of the principals of the invention. Reference
herein to the details of the illustrated embodiments is not intended
to limit the scope of the claims which themselves recite those features
regarded as essential to the invention.